And for much of Wednesday night, The Sounds succeeded in putting on one of the more interactive, lively gigs I've attended. Commanding frontwoman Maja Ivarsson led the audience in singalongs. Bassist Johan Bengtsson, guitarist Felix Rodriguez and keyboardist Jesper Anderberg jumped onto -- yes, onto -- the audience to momentarily crowd surf. The merch table overlords even tossed glow-in-the-dark bracelets to fans before the encore.

But it all started to fall apart near the end.

The key to the Swedish quintet's success is that they just sound good and, um, yes, look very good as well. It's an addictive brand of bubblegum new wave, slightly edgier than Hot-Fuss era Killers. You can't help but dance, despite (or in spite of?) the sometimes cringe-inducing lyrics. There is, sad to say, minimal depth or substance.

What holds it all together is Ivarsson's sassy, powerful vocals. When she sounds good, the band is simply on. When she stumbles off key through entire songs, as she did at the end of their set Wednesday, then they just sound amateur.

There were few signs of trouble early as the band weaved through its three-album discography, naturally playing more numbers off the latest, "Crossing the Rubicon," released in June.

"Dorchester Hotel," about an illicit rendezvous, came with a fast drumbeat and Ivarsson's smoky voice.

"I'm meeting him at London's Dorchester Hotel tonight," she sang in her typically unabashed manner. "If you want to take advantage of him, you know where to go. As long as you bring your Bible you're secure."

The band's lone slow number, "Night After Night," saw Ivarsson solo on stage and puffing from a cigarette. She won street cred points from the cheering audience when she made an obscene motion at the chagrined security guards who came on stage to encourage her to snuff it out.

She later jumped atop the drums and twirled the microphone cord while singing "Painted By Numbers" to Rodriguez's timely guitar shreds and Bengtsson's throbbing bass chords.

"Ladies in the audience!" she yelled out part way through the song. "Where are my b*tches?"

She then led, with limited success, separate groups of women and men in singing lines of "nah, nah, nah." The dodgy line of solo male fans gracing the back of the all-ages section, undoubtedly there to gawk at Ivarsson, seemed to approve.

If only The Sounds had stopped at that point.

Ivarsson sounded terribly off key on the next song, "Ego," the last number of the main set.

Worse yet was the two-song encore, when I'm not sure Ivarsson sang one line of "Tony the Beat" or "Hope You're Happy Now" in tune. She sounded flat, and the songs turned into sonic wrecks.

But The Sounds clearly care about the fan experience, and Ivarsson repeatedly asked the crowd if it was having a good time. And wow, did the fans come decked out, sporting everything from knee-length (faux) animal-print coats to actual animal suits. One guy sported an all-white bunny outfit with a fake gold crown on top.

"Portland, you guys are f***ing nuts," she yelled at one point, "and I love it!"